PEEPS

Aztec Thrush - West Texas

One 10 August a female, ABA Code-4, Aztec Thrush (Ridgwayia pinicola) was found at Frijole Ranch in the Guadalupe Mountains National Park,Texas, by Terry Baldwin.

Aztec Thrush is a Mexican endemic, placed in a monotypic genus, Ridgwayia.  Two subspecies are recognized, one, R. p. pinicola, is found from the Mexican states of Veracruz and Michoacán, south to southern Guerrero and southern Oaxaca.  The other subspecies, R. p. maternalis, occurs from southwest Chihuahua to southern Jalisco in northwest Mexico, the subspecies most likely found in Arizona (Handbook of the Birds of the World, Volume 10).  However, Howell and Webb predict that Aztec Thrush occurs northeast of its described range into northeastern Mexico (Birds of Mexico and Northern Central America, Howell and Webb).  As of 2010, there were only six accepted Texas records of Aztec Thrush, including the first four, two from Big Bend National Park, and  two others from the central coast. The sixth accepted record was a bird from Bentsen-Rio Grande State Park in February, 2010. The first record of this species in the ABA Area came from Boot Spring in the Chisos Mountains, 21−25 August 1977.

Inland Xantus's Murrelet - SoCal

Being compared to Humphrey, the humpback whale, who mysteriously entered San Francisco Bay in 1985 (and again in 1990), swimming into the fresh water of the Sacramento River, an ABA Code 2 Xantus’s Murrelet (Synthliboramphus hypoleucus) was reported by Matt Sadowski on 9 August from the end of 13th Street in Imperial Beach, California.  As recently as 11 August the murrelet has been observed swimming in the Otay River Channel, South San Diego Bay, as much as two miles inland.

Geological history suggests that the northern Pacific Ocean was the center of evolution for most or all of the modern Alcidae (Handbook of the Birds of the World, Volume 3). The living Alcidae comprise 22 species in 11 genera with four members in the genus, Synthliboramphus, all found in the Pacific Ocean (one, Japanese Murrelet out of the ABA Area). Both Xantus’s and Craveri’s murrelets are fish eaters, most often feeding in deeper waters away from coastal areas except during post breeding dispersal. All of the Synthliboramphus murrelets are nocturnal species laying two eggs; they are precocial (and therefore lay the largest eggs in relation to body size.

Both Craveri’s and Xantus’s murrelets have extremely small and restricted populations, earning them the global status of near-threatened. Cat removal from the Channel Islands has had a positive result for Xantus’s Murrelets whose world population is estimated at ~5600 breeding pairs located mainly in four major colonies.

Thick-billed Vireo - South Florida

On 6 August Carlos Sanchez found an ABA Code-4, Thick-billed Vireo (Vireo crassirostris) on the west side of Old Cutler (across from Matheson Hammock) along the Matheson Service Road in Miami/Dade County.  The vireo was later seen by others.

This species is a resident in the Bahamas, Caicos Islands, Tortue Island off of Haiti, Hispaniola, the Cayman Islands, at Isla de Providencia and on St. Catalina Island in the western Caribbean, and recently (1989) on Key Paredón in Cuba (ABA Checklist, Seventh Edition, Pranty et al.).  In Florida it is casual with about 8 records with all records representing the brownish race T. c. crassirostris.  In the Bahamas, Thick-billed Vireo is a common species, however, it is classified as “critically endangered” in Cuba. Florida records include both fall and spring individuals.  The first record for the ABA Area was of three photographed birds from Bill Baggs Cape Florida State Park in from 9 September – 26 October 1989.

Thick-billed Vireo is closely related to 8 other scrub-dwelling vireos including White-eyed of which it is thought to be most closely related and at times considered as a conspecific (Handbook of the Birds of the World, Volume 15).  Even though it is a range-restricted species, Thick-billed Vireo is not globally threatened and it is found in three endemic bird areas, Bahamas, Hispaniola and Cuba EBAs.

Wood Sandpiper - Washington

On 5 August Ryan Merrill, attendee at the 2007 Ecuador ABA Young Adult Conference, found an ABA Code-2 Wood Sandpiper (Tringa glareola) on the Samish Flats in northwestern Washington. Because the bird is in a field on private property, check the WA listserve for instructions for public road (distant) viewing.

Although accidental in the Lower 48, and much more so on the East Coast, Wood Sandpiper is sometimes found in flocks of other Scolpacidae (here with yellowlegs) in northwestern Alaska where it has bred. As the somewhat short bill of this Tringa suggests, members of the tribe, Tringini, forgo the probing style of other sandpipers, instead using their visual acuity to locate prey by running and snatching it in a manner similar to a plover’s foraging style.  An abundant species with an estimated European population of about 1.4 million birds, as many as one million individuals of this long distance migrant winter in Southeast Asia and in east and central Africa (Handbook of the Birds of the World, Volume 3). 

In appearance Wood Sandpiper is most similar to its congener, Green Sandpiper (T. ochropus), although in North America it most closely resembles a Solitary Sandpiper but with longer and slightly more yellowish legs, shorter bill, slightly larger overall and with a less attenuated body.

Aztec Thrush - Arizona

On 1 August a female plumaged, ABA Code-4, Aztec Thrush (Riidgwayia pinicola) was located by Jim Royer, Nick Armstrong, and Leif Rydell along the Carrie Nation Trail in upper Madera Canyon just past its junction with the Vault Mine Trail.  A second bird may also be present.

Aztec Thrush is a Mexican endemic known for its nomadic wanderings and it is the only member of the genus, Ridgwayia. Keep in mind that 1996 and 2006 were invasion years for this species in Southeast Arizona (ABA Checklist, Seventh Edition, Pranty et. al.).  There are records for both New Mexico and South Texas, but most reports and records come from Southeast Arizona, with late July through August producing the most sightings which are often tied to reports of fruiting shrubs in the area (Handbook of the Birds of the World, Vol. 10).  This thrush’s preferred habitats are pine, pine-oak, and pine-evergreen forests and it will join mixed flocks of Turdus thrushes (A Guide to the Birds of Mexico and Northern Central America, Howell and Webb).  This species often sits still for long periods and it is therefore often overlooked (Howell and Webb).

Curlew Sandpipers - Southern California

On 30 July two ABA Code-3 Curlew Sandpipers (Calidris ferruginea) were reported in southern California, one eBird report by Tina Greenawalt was from San Diego NWR and the other was reported from 7^th St Pond in Imperial Beach by Jay Keller.

Curlew Sandpiper is a Eurasian species breeding in low areas in the high Arctic.  Although no subspecies are recognized, females from northeastern Siberia are less darkly barred than females in the western parts of the sandpiper’s range. This long-distance migrant leaves its breeding grounds in July through September. Like many shorebird species, many one-year-old birds remain in their wintering areas throughout the summer (coastal sub-Saharan Africa, India, Australia, and southern Asia). Curlew Sandpipers are more frequently reported from the Atlantic than from the Pacific coast but they have bred in Alaska (The Shorebird Guide, O’Brien et al.).

Curlew Sandpiper has breed with other Calidrids producing some interesting hybrids. The recently discovered "Cox's Sandpiper" has been shown to be a hybrid between Curlew Sandpiper and most likely Pectoral Sandpiper (Handbook of the Birds of the World, Vol. 3).  Mitochondrial DNA of "Cox's Sandpiper" is identical to Curlew Sandpiper DNA and since mitochondrial DNA is inherited, the female parent was a Curlew Sandpiper.  "Cooper's Sandpiper" is now thought to be a hybrid between Curlew Sandpiper and Sharp-tailed Sandpiper. Curlew Sandpiper has also hybridized with White-rumped Sandpiper (HBW, Volume 3).